Skip to content

Without Operations Research, Gridlock!

In many applications, it can be difficult to measure the effect of an operations research project.  For instance, my colleagues and I provide schedules for Major League Baseball.  What is the value added by the operations research we do?  MLB doesn’t have the time, energy or money to handle multiple schedulers in parallel:  they decided five or so years ago that they liked our schedules, and they have been using us since.  We have gotten better over time.  What is the value now?  Who knows?  The non-operations research alternatives no longer provide schedules, and the process, in any case, was not “here’s a schedule, evalute it!”:  it is much more interactive.

gridlockOnce in a while, circumstances come together to show the value of operations research.  If you have been trying to drive anywhere in Montgomery County, Maryland (northwest of Washington, D.C.), you have had a chance to see how traffic systems work without the coordinating effect of operations research systems.  A computer failure messed up the synchronization of traffic signals.  From a Washington Post article:

A computer meltdown disrupted the choreography of 750 traffic lights, turning the morning and evening commutes into endless seas of red brake lights, causing thousands of drivers to arrive at work grumpy and late, and getting them home more frustrated and even later.

The traffic signals didn’t stop working.  They continued, but they no longer changed the time spent “green” in each direction based on time, and they no longer coordinated their “green” cycles along the main corridors:

The system, which she described as “unique” in the Washington region, is based on a Jimmy Carter-era computer that sends signals to traffic lights all over the county. On weekday mornings, it tells them to stay green longer for people headed to work. And in the evenings, it tells them to stay green longer for people headed home.

It also makes them all work together — green-green-green — to promote the flow of traffic. That happens automatically, and then the engineers use data from hundreds of traffic cameras and a county airplane to tweak the system. When there is an accident, breakdown or water main break, they use the computer to adjust signal times further and ease the congestion around the problem.

It’s great when it works, a disaster when it fails.

Of course, without operations research, which determines the correct times and coordinates it across the network, it would be a disaster all the time.  Here’s hoping they get back to the “optimized world” soon (as seems to be the case).

{ 2 } Comments

  1. davidc | November 6, 2009 at 8:40 am | Permalink

    Where are their ‘traffic jams’ that could be removed by OR? Your work presumably stops games piling up and happening all at the same time. Airline and package transport is ORed efficently.

    Hospital waiting situations seem like a traffic jam. What other traffic jams exist?

  2. Don Kleinmuntz | November 7, 2009 at 12:40 pm | Permalink

    Nice example! Now how about Montgomery County designs and implements a system that is resilient enough that there are some backups in place when key components fail? Minimizing the probability of system failure (subject to constraints) is an OR problem too!